The present invention relates to an armature, and more particularly to a fuel injector armature permitting separate fluid and vapor flow.
In the conventional art, it is known to use a fuel injector in an engine compartment of an automobile, for example. It is also known in the conventional art to use an armature in the fuel injector. Fuel flows from an inlet of the fuel injector, through an opening in the armature, to the outlet of the fuel injector. High engine operating temperatures, engine covers, and crowded engine compartments prevent air flow from cooling the fuel injector, which causes fuel disposed within the fuel injector to change from a liquid to a gaseous state (i.e., vaporize). Vaporization is more likely to occur when the engine has been heated (e.g., operated) and is then turned off, since the fuel injector and fuel remain hot, but cool liquid fuel is not being introduced into the system. Vaporized fuel can block the opening in the armature. When the vaporized fuel blocks the opening in the armature, liquid fuel is prevented from flowing through the fuel injector, and reliable engine restarts can be adversely affected. Thus, the engine must cool, thereby allowing the vaporized fuel to condense into a liquid, before the engine can be reliably restarted.
In the conventional art, it is known to cool the engine using a fan. However, this solution requires additional hardware (e.g., fan components), additional room in the engine compartment (e.g., permit adequate air flow paths, install fan components, etc.), and additional manufacturing and maintenance costs. Thus, it is desirable to have an improved fuel injector that dissipates the effects of vapor fuel flow when the engine has been heated and turned off, thereby allowing the engine to be reliably restarted.
The present invention provides a fuel injector. The fuel injector comprises a tube assembly having a longitudinal axis extending between a first end and a second end; a seat secured at the second end of the tube assembly, the seat defining an opening; and an armature assembly movable along the longitudinal axis between first and second positions with respect to the seat. The armature assembly is spaced from the seat such that fuel flow through the opening is permitted in the first position and the armature assembly contiguously engages the seat such that fuel flow through the opening is prevented in the second position. The armature includes a first set of passages permitting a first fluid flow in a first direction generally along the longitudinal axis; and a second set of passages permitting a second fluid flow in a second direction generally along the longitudinal axis, the second direction being generally opposite to the first direction.
The present invention also provides an armature assembly for a fuel injector. The armature moves along a longitudinal axis between first and second positions with respect to a seat having an opening. The armature assembly is spaced from the seat such that fuel flow through the opening is permitted in the first position and the armature assembly contiguously engages the seat such that fuel flow through the opening is prevented in the second position. The armature comprises a first set of passages permitting a first fluid flow in a first direction generally along the longitudinal axis; and a second set of passages permitting a second fluid flow in a second direction generally along the longitudinal axis, the second direction being generally opposite to the first direction.
The present invention also provides a method of dissipating fuel vapor in a fuel injector. The fuel injector has a tube assembly extending along a longitudinal axis between a first end and a second end. A seat is secured at the second end of the tube assembly and defines an opening. And an armature assembly that is movable along the longitudinal axis between first and second positions with respect to the seat. The armature assembly is spaced from the seat such that fuel flow through the opening is permitted in the first position and the armature assembly contiguously engages the seat such that fuel flow through the opening is prevented in the second position. The method comprises providing the armature with a first set of passages permitting liquid fuel flow in a first direction generally from the first end toward the second end; and providing the armature with a second set of passages permitting vapor fuel flow in a second direction generally from the second end toward the first end.